Jeffrey Wang, MD, is co-director of the USC Spine Center at Keck Medicine of USC in Los Angeles and completed his term as president of the North American Spine Society last year.
Dr. Wang spoke to Becker's Spine Review about stem cells and the future of regenerative medicine in spine.
Note: Responses are lightly edited for style and clarity.
Question: Where is regenerative medicine in spine now and where do you think it can go in the next decade?
Dr. Jeffrey Wang: It's very exciting. I've done basic science research ever since I started my practice 22 years ago and I still run my basic science lab. I've always focused on biologics and stem cells. Now the industry is really focused on it so it's great for me. I hope we get more interest, research grants and studies. I think it is the future, however I still have concerns about the lack of data and the marketing.
It's a sexy word so-to-speak, and it attracts patients and the public's attention as well as journals and media publications. It's attractive but we must be scientists about it and ensure we gather the evidence. We need to make sure the public is educated and not just market these therapies if there is no evidence.
Q: How much clinical research has really been done on stem cells in spine?
JW: There are a lot of animal models and some trials that are going on in humans right now. To do an appropriate prospective randomized controlled trial, you need patients, and you need them to understand that as part of the experiment they may not actually get the stem cells. If you Google "stem cells" and regenerative treatments, especially for spine, you're going to get a million hits on websites and people offering stem cells.
Patients could potentially enter a study that has the science behind stem cells but may not actually receive them as part of a controlled trial. I worry that patients may just walk down the street and get "stem cells" from the physician who is advertising it. They don't understand the difference or subtlety. The proliferation of people marketing these stem cell therapies right now, is that going to keep us from getting the real science?
Q: How do you feel about current stem cell therapies in spine?
JW: I have mixed feelings. I'm excited because I think it's the future and that there is interest in it, but I don't want to negatively tarnish someone's reputation. I just want to make sure that physicians who are offering it have evidence. If they do have evidence, publish it and teach us from your experience instead of just looking to get paid.
The other thing is that patients will pay cash for these kinds of therapies. I've seen this with therapies over 20 years ago. Physicians were offering these injections called "disc cure." It wasn't a stem cell, but it was advertised as an alternative to surgery and patients were eating it up and paying cash. There are patients paying cash out of pocket to get these stem cell injections, but there's no evidence behind it and they still need surgery. I just think we need to be as ethical as possible.
Q: What's the going rate for these types of injections? How much are patients willing to pay?
JW: I think some are getting repeat injections and spending anywhere from the high hundreds up to several thousands. I think most physicians who offer them will say there's more benefit if they are serial injections. It's unreasonable to consider injecting stem cells is going to change the body for the remainder of a patient's life so I think stem cell therapies right now are going to require repeat injections.
Q: What do you attribute public interest in stem cells to?
JW: It's multifactorial. It's the new catch phrase. When laser spine surgery first came out, people were attracted to it. It sounds current, contemporary, new and exclusive. People are very attracted to it and I think it's down to the marketing.
Q: Outside of stem cells, is there anything in the regenerative medicine field that you see having an impact in the near future?
JW: I think there are some biologics we do for fusion that, if we get the evidence, can support using classes of products over others. There are products out there now that need evidence. I think growth factors and other inhibitory factors that don't involve stem cells could potentially play a role in disc regeneration and not actually need the cells themselves. There are a lot of potential biologics out there that could help with both fusion, healing incisions, bone healing and maybe saving the disc and preventing it from degenerating. There's a whole lot of potential in biologics that do not revolve around stem cells. You don't necessarily need to use the cells themselves if you find the right biologic.
Putting cells in the disc is not a good environment for the cells. With low PH and low oxygen, cells probably won't survive, but putting in factors that can activate the cells of the disc or the stem cells that we know are inherent in the disc might be the way of the future. It's probably going to be a combination of things. That's where it's going to get tough because each company has its own products — cells, growth factors or inhibitory factors. Maybe if we had a cocktail that had stem cells, inhibitor and promoter factors, that could be the answer. But you would need to get companies together and share their products and I don't know if that's possible.
Q: Outside of biologics, what excites you in spine?
JW: The thing that excites me the most is spinal cord stimulation for patients that are quadriplegic due to spinal cord injuries. There's a lot of smart people out there and the best thing to do is to collaborate. Spine surgeons are somewhat intelligent but there are a lot of basic scientists out there in other areas that may have therapeutics that could be applied to the spine. I think we need to collaborate with scientists in other specialties to come up with the best techniques.